linux-imx

/*

 *  linux/mm/swap.c

 *

 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds

 */

​

/*

 * This file contains the default values for the operation of the

 * Linux VM subsystem. Fine-tuning documentation can be found in

 * Documentation/sysctl/vm.txt.

 * Started 18.12.91

 * Swap aging added 23.2.95, Stephen Tweedie.

 * Buffermem limits added 12.3.98, Rik van Riel.

 */

​

#include <linux/mm.h>

#include <linux/sched.h>

#include <linux/kernel_stat.h>

#include <linux/swap.h>

#include <linux/mman.h>

#include <linux/pagemap.h>

#include <linux/pagevec.h>

#include <linux/init.h>

#include <linux/export.h>

#include <linux/mm_inline.h>

#include <linux/percpu_counter.h>

#include <linux/memremap.h>

#include <linux/percpu.h>

#include <linux/cpu.h>

#include <linux/notifier.h>

#include <linux/backing-dev.h>

#include <linux/memcontrol.h>

#include <linux/gfp.h>

#include <linux/uio.h>

#include <linux/hugetlb.h>

#include <linux/page_idle.h>

​

#include "internal.h"

​

#define CREATE_TRACE_POINTS

#include <trace/events/pagemap.h>

​

/* How many pages do we try to swap or page in/out together? */

int page_cluster;

​

static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);

static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);

static DEFINE_PER_CPU(struct pagevec, lru_deactivate_file_pvecs);

static DEFINE_PER_CPU(struct pagevec, lru_lazyfree_pvecs);

#ifdef CONFIG_SMP

static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);

#endif

​

/*

 * This path almost never happens for VM activity - pages are normally

 * freed via pagevecs.  But it gets used by networking.

 */

static void __page_cache_release(struct page *page)

{

    if (PageLRU(page)) {

        pg_data_t *pgdat = page_pgdat(page);

        struct lruvec *lruvec;

        unsigned long flags;

​

        spin_lock_irqsave(&pgdat->lru_lock, flags);

        lruvec = mem_cgroup_page_lruvec(page, pgdat);

        VM_BUG_ON_PAGE(!PageLRU(page), page);

        __ClearPageLRU(page);

        del_page_from_lru_list(page, lruvec, page_off_lru(page));

        spin_unlock_irqrestore(&pgdat->lru_lock, flags);

    }

    __ClearPageWaiters(page);

    mem_cgroup_uncharge(page);

}

​

static void __put_single_page(struct page *page)

{

    __page_cache_release(page);

    free_unref_page(page);

}

​

static void __put_compound_page(struct page *page)

{

    compound_page_dtor *dtor;

​

    /*

     * __page_cache_release() is supposed to be called for thp, not for

     * hugetlb. This is because hugetlb page does never have PageLRU set

     * (it's never listed to any LRU lists) and no memcg routines should

     * be called for hugetlb (it has a separate hugetlb_cgroup.)

     */

    if (!PageHuge(page))